D3D11_FEATURE_DATA_D3D9_SHADOW_SUPPORT structure (d3d11.h)

Syntax

typedef struct D3D11_FEATURE_DATA_D3D9_SHADOW_SUPPORT {
  BOOL SupportsDepthAsTextureWithLessEqualComparisonFilter;
} D3D11_FEATURE_DATA_D3D9_SHADOW_SUPPORT;

Members

SupportsDepthAsTextureWithLessEqualComparisonFilter

Specifies whether the driver supports the shadowing feature with the comparison-filtering mode set to less than or equal to. The runtime sets this member to TRUE for hardware at Direct3D 10 and higher feature levels. For hardware at Direct3D 9.3 and lower feature levels, the runtime sets this member to TRUE only if the hardware and driver support the shadowing feature; otherwise FALSE.

Remarks

Shadows are an important element in realistic 3D scenes. You can use the shadow buffer technique to render shadows. The basic principle of the technique is to use a depth buffer to store the scene depth info from the perspective of the light source, and then compare each point rendered in the scene with that buffer to determine if it is in shadow.

To render objects into the scene with shadows on them, you create sampler state objects with comparison filtering set and the comparison mode (ComparisonFunc) to LessEqual. You can also set BorderColor addressing on this depth sampler, even though BorderColor isn't typically allowed on feature levels 9.1 and 9.2. By using the border color and picking 0.0 or 1.0 as the border color value, you can control whether the regions off the edge of the shadow map appear to be always in shadow or never in shadow respectively. You can control the shadow filter quality by the Mag and Min filter settings in the comparison sampler. Point sampling will produce shadows with non-anti-aliased edges. Linear filter sampler settings will result in higher quality shadow edges, but might affect performance on some power-optimized devices.

Requirements

See also

Core Structures

D3D11_FEATURE